Environment

LED street lamps deliver 88% power saving in Japan

LED street lamps deliver 88% p...
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March 10, 2009 The cost and energy-efficiency of solid-state lighting are driving many new applications, and the recent installation of the first LED street lights in Osaka Prefecture in Japan, has already been found to provide an overall savings of 88% in electricity bills over the older high-pressure mercury lamps used elsewhere in the region. Each of the LED-based street lamps installed at a park on the Kizu River utilizes 36 cool white LEDs. The LED array generates 30 lux at a pole height of 4.5 meters, comparable to the brightness of mercury lamps, while using just 25 W of power per fixture.

In addition to energy savings, the LUXEON LEDs provided by Philips Lumileds offer a 60,000-hour lifetime (5 to 10 times longer than mercury vapor), mercury-free construction, and the ability to achieve uniform light distribution with minimal glare in street lamp applications because of the greater control over light direction made possible by the small form factor of the LED. Light can be precisely targeted through LED placement and optics optimization.

3 comments
Dr.A.Jagadeesh
The LED array generating 30 lux at a pole height of 4.5 meters, comparable to the brightness of mercury lamps, while using just 25 W of power per fixture is amazing. The trouble with LEDs is that quality LEDs from Japan are excellent, but cheap stuff from countries like China and Korea are poor in quality as developing countries only look for cheap LEDs. I am using Nichia Corporation (Japan) WLED for the last 6 years which is going still strong, where as Rs 100(about 2.5 US $ ) torch lights from China are lost in no time. For developing countries WLEDs make a lot of sense in Energy Conservation. Governments in Developing Countries, NGOs and others who are involved in Rural Electrification will do well to promote WLEDs of quality on a massive scale. Our motto should be each Kwh (Kilowatt Hour) of power saved is each Kwh generated as in Cricket each run saved is each run earned.
Dr.A.Jagadeesh Nellore(AP), India
bruceleed
The LED street lighting is a revolution in the lighting of our cities. Less consumption, longer lasting life, better Ra, less light pollution... many benefits that are easier and easier to get as the LED road lightstechnology become more available. It is true that the replacement with LED requires an investment but thanks to energy savings of around 50% the investment is easily recovered. Using street lamp LED solutions will be soon something as normal as seing LED traffic light in our roads.
William Yoo
It's amazing. Would you explain in detail how to get 88% saving? Generally we can save 50~70% than conventional lamps with LED lamp at present. Even with smart technology,we can save 80%. Korean companies usually use good quality chips like CREE,Nichia,Phillips and Seoul semi-conductor's. Dr.A.Jagadeesh has to be careful to refer others badly with short experiences so that readers recognize your opinion as a valuable one. Mostly,problems occur because of using lower(not in quality, in capacity) chips to reduce cost and SMPS.